1. The Field of the Invention
The present disclosure relates to systems, methods, and containers that sterilize fluids using an electron beam.
2. The Relevant Technology
The biotechnology and pharmaceutical industries are increasingly moving towards the use of disposable polymeric containers and tubing in their manufacturing and processing of sterile liquid product. For example, newly developed bioreactors, which are used in growing cells or microorganisms, commonly comprise a large polymeric bag-like container that is positioned within a rigid support vessel. The cells or microorganisms are grown within the polymeric bag while polymeric tubing coupled with the container is used for adding and removing material from the container. Once a batch is completed, the polymeric bag and tubing are disposed of and a new bag with tubing is used for the next batch. The use of disposable containers and tubing eliminates or at least minimizes the need for cleaning and sterilizing equipment between batches and helps improve quality control.
Although the use of disposable container systems has simplified production and processing, there are still a number of shortcomings with such systems that need to be addressed. One significant issue relates to sterilization. Many biologics are damaged by heat or chemical sterilization. Consequently sterilization is typically done by mechanical filtration. Filtration may be carried out using a membrane with a pore size of 0.2 μm. This pore size is small enough that bacteria cannot pass through. If viruses need to be removed, a much smaller pore size of around 20 nm is needed.
Mechanical filtration is often the limiting factor in the flow rate of the sterilization system. The sterilization filters are usually thin membranes made from nitrocellulose or polyethersulfone (PES). The membranes are relatively fragile, which limits the amount of pressure that can be applied. The relatively low pressure and small pore size results in relatively low flow rates. In addition, the filters can be expensive to manufacture and have to be replaced frequently, thereby increasing the cost and complexity of using the system.
Accordingly, what is needed in the art are sterilization systems that avoid the flow restrictions and/or other shortcomings caused by mechanical filters with small pore diameters.